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Test Code LAB814 Calcium, 24 Hour Urine

Useful For

  • Evaluation of calcium oxalate and calcium phosphate kidney stone risk, and calculation of urinary supersaturations
  • Evaluation of bone diseases, including osteoporosis and osteomalacia

Methodology

Photometric, 5-nitro-5'-methyl-BAPTA

Performing Laboratory

Bozeman Health Laboratory Services

Specimen Requirements

Specimen Type: Urine
Container/Tube: 24-hour urine collection container
Specimen Volume: Entire collection
Specimen Minimum Volume: 1 mL
Collection Instructions:

  1. Collect a 24-hour urine specimen.
  2. Starting and ending times of collection are required.
  3. Refrigerate specimen during collection.
  4. Add 20-30 mL of 6 mol/L HCl within 4 hours of collection to prevent calcium salt precipitation. 
  5. Mix well before taking aliquot.

Additional Information:

  1. If HCL is not available, keep specimen refrigerated and analyze promptly.
  2. Follow special collection instructions below:

Special Instructions

Specimen Transport Temperature

Refrigerated

Specimen Stability

Specimen Type Temperature Time
24-hour urine collection Refrigerated

4 days

Reference Values

100.0 - 300.0 mg/24 hours

Day(s) Test Set Up

Monday through Sunday

Test Classification and CPT Coding

82340-Calcium

81050-Urine timed measurement (if appropriate)